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Santos X, Chergui B, Belliure J, Moreira F, Pausas JG. Reptile responses to fire across the western Mediterranean Basin. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2024:e14326. [PMID: 38949049 DOI: 10.1111/cobi.14326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 04/23/2024] [Accepted: 04/26/2024] [Indexed: 07/02/2024]
Abstract
Effects of anthropogenic activities, including climate change, are modifying fire regimes, and the dynamic nature of these modifications requires identification of general patterns of organisms' responses to fire. This is a challenging task because of the high complexity of factors involved (including climate, geography, land use, and species-specific ecology). We aimed to describe the responses of the reptile community to fire across a range of environmental and fire-history conditions in the western Mediterranean Basin. We sampled 8 sites that spanned 4 Mediterranean countries. We recorded 6064 reptile sightings of 36 species in 1620 transects and modeled 3 community metrics (total number of individuals, species richness, and Shannon diversity) as responses to environmental and fire-history variables. Reptile community composition was also analyzed. Habitat type (natural vs. afforestation), fire age class (time since the last fire), rainfall, and temperature were important factors in explaining these metrics. The total number of individuals varied according to fire age class, reaching a peak at 15-40 years after the last fire. Species richness and Shannon diversity were more stable during postfire years. The 3 community metrics were higher under postfire conditions than in unburned forest plots. This pattern was particularly prevalent in afforested plots, indicating that the negative effect of fire on reptiles was lower than the negative effect of afforestation. Community composition varied by fire age class, indicating the existence of early- and late-successional species (xeric and saxicolous vs. mesic reptiles, respectively). Species richness was 46% higher in areas with a single fire age class relative to those with a mixture of fire age classes, which indicates pyrodiverse landscapes promoted reptile diversity. An expected shift to more frequent fires will bias fire age distribution toward a predominance of early stages, and this will be harmful to reptile communities.
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Affiliation(s)
- Xavier Santos
- CIBIO/InBIO (Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | - Brahim Chergui
- Laboratoire Ecologie, Systématique, Conservation de la Biodiversité, LESCB URL-CNRST N°18, FS, Abdelmalek Essaadi University, Tétouan, Morocco
| | - Josabel Belliure
- Global Change Ecology and Evolution Research Group (GloCEE), Department of Life Sciences, University of Alcalá, Madrid, Spain
| | - Francisco Moreira
- CIBIO/InBIO (Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
- Research Centre in Biodiversity and Genetic Resources/Research Network in Biodiversity and Evolutionary Biology (CIBIO/InBIO), School of Agriculture, University of Lisbon, Lisboa, Portugal
| | - Juli G Pausas
- Centro de Investigaciones sobre Desertificación (CIDE-CSIC), Moncada, Spain
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Puig-Gironès R, Santos X, Bros V. Long-interval effects of wildfires on the functional diversity of land snails. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 876:162677. [PMID: 36894101 DOI: 10.1016/j.scitotenv.2023.162677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 03/02/2023] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
In fire-prone regions, fire is a major natural disturbance which shapes ecosystem function and community composition. Fire has a direct and dramatic effect on soil fauna and, especially, on non-mobile species such as land snails. The factors that make the Mediterranean Basin a fire-prone region may also lead to the appearance after fires of certain functional traits related to ecological and physiological characteristics. Knowledge of how community structure and function change along the post-fire succession will be useful for understanding the processes that drive biodiversity patterns in burnt areas and for implementing appropriate biodiversity management strategies. Here, we examine long-interval taxonomic and functional changes occurred in a snail community four and 18 years after a fire in the Sant Llorenç del Munt i l'Obac Natural Park (NE Spain). Our field-based study demonstrates that the land snail assemblage responds both taxonomically and functionally to fire and that there was a clear replacement of dominant species from the first to the second sampling period. Variation in community composition between different post-fire ages can be attributed to snail species traits and successional changes in post-fire habitat conditions. At taxonomic level, there was great variation in snail species turnover between both periods, being the development of the understorey vegetation structure the main driver of this variation. The replacement of functional traits between times since fire suggests that xerophilic and mesophilic preferences play an important role after fire and are largely determined by the complexity of post-fire microhabitats. Our analysis indicates that immediately after a fire there is a time-window of opportunity that attracts species specializing in early successional habitats, which thereafter are replaced due to the changing conditions resulting from succession. Consequently, knowing the functional traits of species is important for determining the impacts of disturbances on the taxonomic and functional communities.
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Affiliation(s)
- Roger Puig-Gironès
- Departament de Ciències Ambientals, Universitat de Girona, C. Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain; Equip de Biologia de la Conservació, Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals & Institut de la Recerca de la Biodiversitat (IRBIO), Universitat de Barcelona, Av. Diagonal 643, 08028 Barcelona, Catalonia, Spain.
| | - Xavier Santos
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, R. Padre Armando Quintas s/n, 4485-661 Vairão, Portugal
| | - Vicenç Bros
- Oficina Tècnica de Parcs Naturals, Diputació de Barcelona, Urgell 187, 08036 Barcelona, Catalonia, Spain
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Wanniarachchi S, Swan M, Nevil P, York A. Using eDNA metabarcoding to understand the effect of fire on the diet of small mammals in a woodland ecosystem. Ecol Evol 2022; 12:e9457. [PMID: 36381390 PMCID: PMC9643072 DOI: 10.1002/ece3.9457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/30/2022] [Accepted: 10/05/2022] [Indexed: 11/11/2022] Open
Abstract
Food acquisition is a fundamental process that drives animal distribution and abundance, influencing how species respond to changing environments. Disturbances such as fire create significant shifts in available dietary resources, yet, for many species, we lack basic information about what they eat, let alone how they respond to a changing resource base. In order to create effective management strategies, faunal conservation in flammable landscapes requires a greater understanding of what animals eat and how this change following a fire. What animals eat in postfire environments has received little attention due to the time-consuming methodologies and low-resolution identification of food taxa. Recently, molecular techniques have been developed to identify food DNA in scats, making it possible to identify animal diets with enhanced resolution. The primary aim of this study was to utilize eDNA metabarcoding to obtain an improved understanding of the diet of three native Australian small mammal species: yellow-footed antechinus (Antechinus flavipes), heath mouse (Pseudomys shortridgei), and bush rat (Rattus fuscipes). Specifically, we sought to understand the difference in the overall diet of the three species and how diet changed over time after fire. Yellow-footed antechinus diets mostly consisted of moths, and plants belonging to myrtles and legume families while bush rats consumed legumes, myrtles, rushes, and beetles. Heath mouse diet was dominated by rushes. All three species shifted their diets over time after fire, with most pronounced shifts in the bush rats and least for heath mice. Identifying critical food resources for native animals will allow conservation managers to consider the effect of fire management actions on these resources and help conserve the species that use them.
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Affiliation(s)
- Saumya Wanniarachchi
- School of Ecosystem and Forest SciencesThe University of MelbourneCreswickVictoriaAustralia
| | - Matthew Swan
- School of Ecosystem and Forest SciencesThe University of MelbourneCreswickVictoriaAustralia
| | - Paul Nevil
- Trace and Environmental DNA Laboratory, School of Life and Molecular SciencesCurtin UniversityPerthWestern AustraliaAustralia
| | - Alan York
- School of Ecosystem and Forest SciencesThe University of MelbourneCreswickVictoriaAustralia
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Doherty TS, Geary WL, Jolly CJ, Macdonald KJ, Miritis V, Watchorn DJ, Cherry MJ, Conner LM, González TM, Legge SM, Ritchie EG, Stawski C, Dickman CR. Fire as a driver and mediator of predator-prey interactions. Biol Rev Camb Philos Soc 2022; 97:1539-1558. [PMID: 35320881 PMCID: PMC9546118 DOI: 10.1111/brv.12853] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 03/15/2022] [Accepted: 03/16/2022] [Indexed: 01/08/2023]
Abstract
Both fire and predators have strong influences on the population dynamics and behaviour of animals, and the effects of predators may either be strengthened or weakened by fire. However, knowledge of how fire drives or mediates predator–prey interactions is fragmented and has not been synthesised. Here, we review and synthesise knowledge of how fire influences predator and prey behaviour and interactions. We develop a conceptual model based on predator–prey theory and empirical examples to address four key questions: (i) how and why do predators respond to fire; (ii) how and why does prey vulnerability change post‐fire; (iii) what mechanisms do prey use to reduce predation risk post‐fire; and (iv) what are the outcomes of predator–fire interactions for prey populations? We then discuss these findings in the context of wildlife conservation and ecosystem management before outlining priorities for future research. Fire‐induced changes in vegetation structure, resource availability, and animal behaviour influence predator–prey encounter rates, the amount of time prey are vulnerable during an encounter, and the conditional probability of prey death given an encounter. How a predator responds to fire depends on fire characteristics (e.g. season, severity), their hunting behaviour (ambush or pursuit predator), movement behaviour, territoriality, and intra‐guild dynamics. Prey species that rely on habitat structure for avoiding predation often experience increased predation rates and lower survival in recently burnt areas. By contrast, some prey species benefit from the opening up of habitat after fire because it makes it easier to detect predators and to modify their behaviour appropriately. Reduced prey body condition after fire can increase predation risk either through impaired ability to escape predators, or increased need to forage in risky areas due to being energetically stressed. To reduce risk of predation in the post‐fire environment, prey may change their habitat use, increase sheltering behaviour, change their movement behaviour, or use camouflage through cryptic colouring and background matching. Field experiments and population viability modelling show instances where fire either amplifies or does not amplify the impacts of predators on prey populations, and vice versa. In some instances, intense and sustained post‐fire predation may lead to local extinctions of prey populations. Human disruption of fire regimes is impacting faunal communities, with consequences for predator and prey behaviour and population dynamics. Key areas for future research include: capturing data continuously before, during and after fires; teasing out the relative importance of changes in visibility and shelter availability in different contexts; documenting changes in acoustic and olfactory cues for both predators and prey; addressing taxonomic and geographic biases in the literature; and predicting and testing how changes in fire‐regime characteristics reshape predator–prey interactions. Understanding and managing the consequences for predator–prey communities will be critical for effective ecosystem management and species conservation in this era of global change.
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Affiliation(s)
- Tim S Doherty
- School of Life and Environmental Sciences, Heydon-Laurence Building A08, The University of Sydney, Sydney, NSW, 2006, Australia
| | - William L Geary
- Biodiversity Strategy and Knowledge Branch, Biodiversity Division, Department of Environment, Land, Water and Planning, 8 Nicholson Street, East Melbourne, VIC, 3002, Australia.,Centre for Integrative Ecology, School of Life and Environmental Sciences (Burwood Campus), Deakin University, 75 Pigdons Road, Waurn Ponds, VIC, 3216, Australia
| | - Chris J Jolly
- School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Gungalman Drive, Albury, NSW, 2640, Australia.,School of Natural Sciences, G17, Macquarie University, 205B Culloden Road, Macquarie Park, NSW, 2109, Australia
| | - Kristina J Macdonald
- Centre for Integrative Ecology, School of Life and Environmental Sciences (Burwood Campus), Deakin University, 75 Pigdons Road, Waurn Ponds, VIC, 3216, Australia
| | - Vivianna Miritis
- School of Life and Environmental Sciences, Heydon-Laurence Building A08, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Darcy J Watchorn
- Centre for Integrative Ecology, School of Life and Environmental Sciences (Burwood Campus), Deakin University, 75 Pigdons Road, Waurn Ponds, VIC, 3216, Australia
| | - Michael J Cherry
- Caesar Kleberg Wildlife Research Institute, Texas A&M University-Kingsville, 700 University Boulevard, MSC 218, Kingsville, TX, 78363, U.S.A
| | - L Mike Conner
- The Jones Center at Ichauway, 3988 Jones Center Drive, Newton, GA, 39870, U.S.A
| | - Tania Marisol González
- Laboratorio de Ecología del Paisaje y Modelación de Ecosistemas ECOLMOD, Departamento de Biología, Facultad de Ciencias, Universidad Nacional de Colombia, Edificio 421, Bogotá, 111321, Colombia
| | - Sarah M Legge
- Fenner School of Environment & Society, The Australian National University, Linnaeus Way, Canberra, ACT, 2601, Australia.,Centre for Biodiversity Conservation Science, University of Queensland, Level 5 Goddard Building, St Lucia, QLD, 4072, Australia
| | - Euan G Ritchie
- Centre for Integrative Ecology, School of Life and Environmental Sciences (Burwood Campus), Deakin University, 75 Pigdons Road, Waurn Ponds, VIC, 3216, Australia
| | - Clare Stawski
- Department of Biology, Norwegian University of Science and Technology, Trondheim, NO-7491, Norway.,School of Science, Technology and Engineering, University of the Sunshine Coast, Maroochydore DC, QLD, 4558, Australia
| | - Chris R Dickman
- School of Life and Environmental Sciences, Heydon-Laurence Building A08, The University of Sydney, Sydney, NSW, 2006, Australia
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Santos X, Belliure J, Gonçalves JF, Pausas JG. Resilience of reptiles to megafires. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2518. [PMID: 34918831 DOI: 10.1002/eap.2518] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 07/13/2021] [Accepted: 08/25/2021] [Indexed: 06/14/2023]
Abstract
Extreme climate events, together with anthropogenic land-use changes, have led to the rise of megafires (i.e., fires at the top of the frequency size distribution) in many world regions. Megafires imply that the center of the burnt area is far from the unburnt; therefore, recolonization may be critical for species with low dispersal abilities such as reptiles. We aimed to evaluate the effect of megafires on a reptile community, exploring to what extent reptile responses are spatially shaped by the distance to the unburnt area. We examined the short-term spatiotemporal response of a Mediterranean reptile community after two megafires (>20,000 ha) that occurred in summer 2012 in eastern Spain. Reptiles were sampled over 4 years after the fire in burnt plots located at different distances from the fire perimeter (edge, middle, and center), and in adjacent unburnt plots. Reptile responses were modeled with fire history, as well as climate and remotely sensed environmental variables. In total, we recorded 522 reptiles from 12 species (11 species in the burnt plots and nine in the unburnt plots). Reptile abundance decreased in burnt compared with unburnt plots. The community composition and species richness did not vary either spatially (unburnt and burnt plots) or temporally (during the 4 years). The persistence of reptiles in the burnt area supported their resilience to megafires. The most common lizard species was Psammodromus algirus; both adults and juveniles were found in all unburnt and burnt plots. This species showed lower abundances in burnt areas compared with the unburnt and a slow short-term abundance recovery. The lizard Psammodromus edwarsianus was much less abundant and showed a tendency to increase its abundance in burnt plots compared with unburnt plots. Within the megafire area, P. algirus and P. edwarsianus abundances correlated with the thermal-moisture environment and vegetation recovery regardless of the distance from the fire edge. These results indicated the absence of a short-term reptile recolonization from the unburnt zone, demonstrating that reptiles are resilient (in situ persistence) to megafires when environmental conditions are favorable.
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Affiliation(s)
- Xavier Santos
- CIBIO/InBIO, Research Centre in Biodiversity and Genetic Resources, University of Porto. Instituto de Ciências Agrárias de Vairão. R. Padre Armando Quintas, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | - Josabel Belliure
- Departamento de Ciencias de la Vida, Global Change Ecology and Evolution Group (GLOCEE), Universidad de Alcalá, Madrid, Spain
| | - João F Gonçalves
- CIBIO/InBIO, Research Centre in Biodiversity and Genetic Resources, University of Porto. Instituto de Ciências Agrárias de Vairão. R. Padre Armando Quintas, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
- proMetheus - Research Unit in Materials, Energy and Environment for Sustainability, Instituto Politécnico de Viana do Castelo (IPVC), Avenida do Atlântico, Viana do Castelo, Portugal
| | - Juli G Pausas
- Centro de Investigaciones sobre Desertificación (CIDE-CSIC), Moncada, Spain
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Chergui B, Pleguezuelos JM, Fahd S, Santos X. Modelling functional response of reptiles to fire in two Mediterranean forest types. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 732:139205. [PMID: 32438172 DOI: 10.1016/j.scitotenv.2020.139205] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/01/2020] [Accepted: 05/02/2020] [Indexed: 06/11/2023]
Abstract
Fire is one of the main disturbances to terrestrial environments, transforming habitat structure and affecting community composition. Coupled with fire, forest type and vegetation structure modulate the taxonomic response to fire by ectotherm organisms such as reptiles. The response of each reptile species to fire is based on their functional attributes, which make some species resilient to fire and others vulnerable to that disturbance and only adapted to long-unburnt landscapes. We studied the functional response of a reptile community at 13 burnt sites within the African rim of the Western Mediterranean, and in two contrasting forest types, i.e. native cork oak forests (five sites) and pine plantations (eight sites). We compiled seven functional traits for the reptile species in the study areas, and quantified reptile functional diversity at each sampled plot. Variation in this index was examined from burnt to nearby unburnt plots, both in cork oak and pine forests, with generalized linear mixed models. Redundancy analysis was used to identify which functional traits were associated with particular plot types. We found 2149 individual reptiles from 15 species. The functional response of reptiles to fire was forest-type dependent: functional richness did not change with fire in cork oak forest plots, but increased with fire in the pine plantation ones. High reptile functional richness in cork oak plots was due to high species richness in this forest type. The functional-redundancy analysis showed that cork oak forest hosts a reptile community functionally composed of small Mediterranean ground- and rock-dwelling lizards. In pine plantation plots, however, saxicolous geckos and phytophagous tortoises indicate the availability of other microhabitat and food resources to be exploited by reptile species with different functional traits.
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Affiliation(s)
- Brahim Chergui
- Equipe de Recherche Ecologie, Systématique, Conservation de la Biodiversité, Faculté des Sciences de Tétouan, Université Abdelmalek Essaâdi, BP 2121 El M'Hannech, Tétouan, Morocco.
| | - Juan M Pleguezuelos
- Departamento de Zoología, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain
| | - Soumia Fahd
- Equipe de Recherche Ecologie, Systématique, Conservation de la Biodiversité, Faculté des Sciences de Tétouan, Université Abdelmalek Essaâdi, BP 2121 El M'Hannech, Tétouan, Morocco
| | - Xavier Santos
- CIBIO/InBIO (Centro de Investigação em Biodiversidade e Recursos Genéticos da Universidade do Porto), R. Padre Armando Quintas, 4485-661 Vairão, Portugal
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Geary WL, Doherty TS, Nimmo DG, Tulloch AIT, Ritchie EG. Predator responses to fire: A global systematic review and meta-analysis. J Anim Ecol 2019; 89:955-971. [PMID: 31774550 DOI: 10.1111/1365-2656.13153] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 10/03/2019] [Indexed: 01/13/2023]
Abstract
Knowledge of how disturbances such as fire shape habitat structure and composition, and affect animal interactions, is fundamental to ecology and ecosystem management. Predators also exert strong effects on ecological communities, through top-down regulation of prey and competitors, which can result in trophic cascades. Despite their ubiquity, ecological importance and potential to interact with fire, our general understanding of how predators respond to fire remains poor, hampering ecosystem management. To address this important knowledge gap, we conducted a systematic review and meta-analysis of the effects of fire on terrestrial, vertebrate predators world-wide. We found 160 studies spanning 1978-2018. There were 36 studies with sufficient information for meta-analysis, from which we extracted 96 effect sizes (Hedges' g) for 67 predator species relating to changes in abundance indices, occupancy or resource selection in burned and unburned areas, or before and after fire. Studies spanned geographic locations, taxonomic families and study designs, but most were located in North America and Oceania (59% and 24%, respectively), and largely focussed on felids (24%) and canids (25%). Half (50%) of the studies reported responses to wildfire, and nearly one third concerned prescribed (management) fires. There were no clear, general responses of predators to fire, nor relationships with geographic area, biome or life-history traits (e.g. body mass, hunting strategy and diet). Responses varied considerably between species. Analysis of species for which at least three effect sizes had been reported in the literature revealed that red foxes Vulpes vulpes mostly responded positively to fire (e.g. higher abundance in burned compared to unburned areas) and eastern racers Coluber constrictor negatively, with variances overlapping zero only slightly for both species. Our systematic review and meta-analysis revealed strong variation in predator responses to fire, and major geographic and taxonomic knowledge gaps. Varied responses of predator species to fire likely depend on ecosystem context. Consistent reporting of ongoing monitoring and management experiments is required to improve understanding of the mechanisms driving predator responses to fire, and any broader effects (e.g. trophic interactions). The divergent responses of species in our study suggest that adaptive, context-specific management of predator-fire relationships is required.
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Affiliation(s)
- William L Geary
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Geelong/Burwood, Vic., Australia.,Biodiversity Division, Department of Environment, Land, Water & Planning, East Melbourne, Vic., Australia
| | - Tim S Doherty
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Geelong/Burwood, Vic., Australia
| | - Dale G Nimmo
- School of Environmental Science, Institute for Land, Water and Society, Charles Sturt University, Albury, NSW, Australia
| | - Ayesha I T Tulloch
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
| | - Euan G Ritchie
- School of Life and Environmental Sciences, Centre for Integrative Ecology, Deakin University, Geelong/Burwood, Vic., Australia
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Increase of genetic diversity indicates ecological opportunities in recurrent-fire landscapes for wall lizards. Sci Rep 2019; 9:5383. [PMID: 30926838 PMCID: PMC6441018 DOI: 10.1038/s41598-019-41729-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 03/15/2019] [Indexed: 12/02/2022] Open
Abstract
Socioeconomic and climatic factors are modifying fire regimes with an increase of fire frequency and extension. Unfortunately, the effects of recurrent fires on biological processes that ultimately affect the genetic diversity of animal populations are mostly unknown. We examined genetic patterns of diversity in the wall lizard Podarcis guadarramae in northern Portugal, one of the European regions with the highest percentage of burnt land. This species is a small saxicolous lizard as it inhabits natural outcrops and artificial stone walls, likely in recurrent-fire landscapes. We genotyped nine microsatellites from ten populations selected according to a gradient in fire recurrence, and compared genetic diversity indexes and demographic patterns among them. At the population level, we hypothesize that a high level of mortality and population bottlenecks are expected to reduce genetic heterozygosity in sampled localities affected by recurrent fires. Alternatively, genetic signatures are expected to be absent whether fire did not cause high mortality. Regardless of levels of mortality, we expect a gain in genetic diversity whether recurrent fires facilitate lizard dispersal and migration due to the increased quality of the habitat for wall lizards. At the regional level, we examine whether a recurrent fire regime may disrupt the spatial structure of populations. Our results showed an increase in genetic diversity in recurrently burnt populations, and a decline in longer-unburnt populations. We did not detect bottleneck effects in repeatedly-burnt populations. High genetic diversity in recurrent fire populations suggests a high dispersion rate between adjacent metapopulations and perhaps immigration from outside the fire boundary. At the regional level, lizard populations show low differentiation and weak genetic structure, suggesting no effects of fire. This study confirms field-based censuses showing that recurrent-fire regimes give ecological opportunities to wall lizards that benefit from habitat openness.
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Dixon KM, Cary GJ, Worboys GL, Gibbons P. The disproportionate importance of long-unburned forests and woodlands for reptiles. Ecol Evol 2018; 8:10952-10963. [PMID: 30519419 PMCID: PMC6262929 DOI: 10.1002/ece3.4561] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 08/23/2018] [Accepted: 08/28/2018] [Indexed: 11/10/2022] Open
Abstract
Our understanding of the impacts of time since fire on reptiles remains limited, partly because there are relatively few locations where long-term, spatially explicit fire histories are available. Such information is important given the large proportion of some landscapes that are managed with frequent prescribed fire to meet fuel management objectives. We conducted a space-for-time study across a landscape in southeastern Australia where the known fire history spanned 6 months to at least 96 years. Four methods were used to survey reptiles in 81 forest and woodland sites to investigate how time since fire (TSF), habitat, and environmental variables affect reptile richness, abundance, and composition. We used generalized linear models, generalized linear mixed-effects models, PERMANOVA, and SIMPER to identify relationships between the reptile assemblage (richness, abundance, and composition, respectively) and TSF, habitat, and environmental variables. All three reptile metrics were associated with TSF. Reptile richness and abundance were significantly higher in sites >96 years postfire than younger fire ages (0.5-12 years). Reptile composition at long-unburned sites was dissimilar to sites burned more recently but was similar between sites burned 0.5-2 and 6-12 years prior to sampling. Synthesis and applications. Long-unburned forests and woodlands were disproportionately more important for reptile richness and abundance than areas burned 6 months to 12 years prior to sampling. This is important given that long-unburned areas represent <8% of our study area. Our results therefore suggest that reptiles would benefit from protecting remaining long-unburned areas from fire and transitioning a greater proportion of the study area to long-unburned. However, some compositional differences between the long-unburned sites and sites 0.5-12 years postfire indicate that maintaining a diversity in fire ages is important for conserving reptile diversity.
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Affiliation(s)
- Kelly M. Dixon
- Fenner School of Environment and SocietyThe Australian National UniversityActonACTAustralia
| | - Geoffrey J. Cary
- Fenner School of Environment and SocietyThe Australian National UniversityActonACTAustralia
| | - Graeme L. Worboys
- Fenner School of Environment and SocietyThe Australian National UniversityActonACTAustralia
| | - Philip Gibbons
- Fenner School of Environment and SocietyThe Australian National UniversityActonACTAustralia
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